Process of making borax.



UNITEDSTATES PATENT onnion GILBERT E. BAILEY, OF LOS ANGELES, CALIFORNIA, ASSIGNOR OF ONE-HALF Tb ARCHIE STEVENSON, OF LOS ANGELES, CALIFORNIA.

rnocsss or Maxine BOBAX.

Specification of Letters Patent.

Patented Feb. 9, 1909.

K Application filed September 15, 1908. SeiialNo. 453,169.

. To all whom it may concern:

Be it known that I, GILBERT E. BAILEY, a

citizen of the United States, residing at Los sulfate; Compounds containing 'boron and, lime or boron and magnesia belong to this the acid class and such compounds are of abundantoccurrence in some localities and afford a suitable source for the economical production of borax. In the production of borax from such compounds, as carried out in the process now in general use, it is necessary to manufacture boric, acid from the borate of lime, etc., and then obtain borax by treating the acid with sodium carbonate; or to boil the sodium carbonate for a long time with the floured borate of lime to form borax and insoluble lime salts. Either of these processes is necessarily eipensive.

-The main object of the present invention is to reduce the cost of production of borax f1'0I1Tt-l16 native borates of the-classes-speci- '30 fi My process is applicable to any native (na.tural) mineral borates. wherein the base and is intended particularly for the production of borax from natural borates of lime such as the minerals known as colemanite, pandermrte, pricelte, I p slne, etc. The process 15 not confinedhowulexite bechelite,.hayeever to the minerals principally composed of boronand lime, but may be used to form borates of soda from minerals consisting largely of' boron and magnesium, such as boracite, hydroboracite, pinnoite, etc, and to all minerals or ores in. a native condition containing boron united to calcium or magnesium, or other base that 'will unite with part of sodium sulfate setting the boron free to unite with the basic (sodium) partof sodium sulfate; forming borax or other'borates of sodium.

The process consists essentially in roasting the native borate of lime or magnesium with sodium sulfate, causing a double reaction resulting in formation, on the one hand, of sodium tetraborate (borax) which is soluble the solution --jected to tli 7 is capable of forming an insoluble sulfate roll on wheels 7, provided with driving tents in water, and, onthe other hand, of insolu-, blelime or magnesium salts; leaching out the borax with boiling water and preclpltat- 'ingor crystallizing the bora'x from the solution. a

The borax may be separated for use from by the usual manner, but it is preferred-to separate the borax from the solution by chilling the solution down to about 32 degrees F.

The accompanying drawings illustrate an apparatus suitable for carrying outj the process.

Figure 1 is an elevation of the furnace 9 and piping with the leaching and precipitating tanks in section.- Fig. 2 isalongitu-,- dinal s ection of the furnace, v

In said drawings 1 designates the furnace whichmay beareverberatory furnace,but for obtaining the best 0peration,'it' is preferred to use a revolving-furnace such as is used in making soda ash'by the L'eBlanc process. Said furnace is preferably heated by a flame froma distillate "or crude oil burner, indi-, cated at'2, but any flame moderately free from soot may be used. I

3 designates the leaching tank, in which the furnace product is placed and leached wit-h boilingjwater. i

5 designates the precipitating tank, where in the liquor from the leaching tank is sub e action of the cooling coil 6. Furnace 1 consists of a barrel mounted to means 8 to rotate the barrel. Said. barrel has a charging and discharging opening provided with -a closure 9. One end of barrel. 1 has an'opening 10, into which the flame from burner 2 is directed to heat the conof the barrel,. as said contents are or tumbled in the rotation of the barrel., Barrel 1 has a lining, indicated atQfi, with projections 26, to lift the matenial. The otherend of the barrel l'has, an outlet 11, discharging the waste gases into "a suit-' able flue, as into a chamber 12, communicating-with a stack 13, said chamber l2con-' taining an evaporating pan 14 which maybe rolled used to evaporate any of the solutions pro- Transportation means m .28, 29 are provided for charging the furnace duced in the process.

and removing the charge from the furnace to the leaching tank. Leaching tank 3 has a series of draw-off plugs 15 located atdifferent'heights, so as in the tank.

' sump 22 back to the leaching tank, through intake heating means, indicated at 23, which may be located in chamber 12 of the furnace.

The process is carried out as follows: The ore or native compound'of boron with lime or magnesium, for example, borate oflime (eolemanite, 'pa'ndermite, etc.) is first c 'nshed to'moderate fineness, from about 10 mesh to kernel of cormsize is found to be fine enough. The smaller the charge the finer the crushing. The crushed material is then mixed with sodium sulfate in about molecular proportions, care being taken to provide that the sodium is in slight excess of the quantity necessary to combine with the boron. In so mixing the sodium sulfate with the borate of lime, etc, the sodium sulfate should bein a sufficiently divided condition to permit of uniform mixture and maybe air dried or moderately hard but neet not be anhydrous. The charge formed of this mixture is plaeed in the furnace 1 and heated slowly to bri red heat. It is not desirable to heat the charge too rapidly, or to heat it until .it'fuses, as this produces a hard compound difficult to leach. Slow heating to a bright red all. through the mass, and holding such heat for a few minutes gives the best results. In the case of colemanite Ca B O HT O the chemical reaction is represented by the-equation The colemanite and the sodium sulfate lose their water of crystallization during the roasting. T he charge is then transferred to the tank or receptacle 3 and trcrted with boiling water supplied by the pipe 1 until all the borax is extracted. In practice it is best to treat the mass by successive portions of the boiling water or wet steam, drawing but it is preferred the water off and repeating the-operation as the water becomes saturated. The solution so drawn off may be settled, evaporated or crystallized by any of the ordinary methods; to chill the solution at once, as by passing it into the refrigerating 1 tank 5, wherein the b0 ax is nearly all pro eipitated at 32 to 34- degrees F, yielding the borax in a fine powder and saving tedious crystallization followed by grinding. The liquor remaining in the refrigerating tank after precipitation can be pumped or drawn back to the heating means 23, and after beingheated to boiling tenmeratin'e can be used ove again in the leaching tank, thus saving any portion of tetraborate which is not precipitated.

In case a refrigerating plant is not available, the borax liquor may be evaporated. down in the pan 14., heated by the waste gases of: the furnace, the borax being then crystallized out.

What I claim is:

1. The process of manufacturing borax direct from a borate of a metal capable of forming an insoluble sulfate which consists in roasting said borate with sodium sulfate, leaching the roasted product and separating the dissolved borax from the leaching liquor.

2. The process of producing a borate of sodium from the native ores containing a borate of a metal capable of forming an insoluble sulfate which consists in roasting said ores with sodium sulfate; leaching the roasted product, and separating the dissolved sodium boate from the leaching liquor.

3. The process of producing borax from native borates of lime and magnesia which consists in roasting said native borates with sodium sulfate; leaching the roasted product; removing the leaching liquor from the product, and cooling the said liquor nearly to the freezing point of water, thereby precipitating boraX therefrom in a finely divided state.

In testimony whereof, I have hereunto set my hand at Les Angcles, California, this 3rd daypf September. 190R.

GTLBERT E. BAULEY. in presence of Airmen I. KMoi-rr, Farm; L. A. GRAHAM. 

